<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<select name="country">
    <option value="">请选择国家</option>
    <optgroup label="chinese">
    <option value="cn"> 中国</option>
    </optgroup>
    <option value="us"> 美国</option>
</select>

    <input type="radio" name="gender" value="male" id="male">
    <label for="male">男</label>

    <input type="radio" name="gender" value="female" id="female">
    <label for="female">女</label>



<label>
    <input type="checkbox" name="hobby" value="music" checked> 音乐
</label>
<label>
    <input type="checkbox" name="hobby" value="sports"> 运动
</label>
<label>
    <input type="checkbox" name="hobby" value="reading"> 阅读
</label>

<button type="button" onclick="alert('点击')">普通按钮</button>

<!-- 等价于 -->
<input type="submit" value="提交">
</body>
</html>